Silicon photovoltaic panels typically have a protective top layer of cover glass or plastic to protect the underlying photovoltaic cells. Enhanced performance coatings such as thin-film energy transmission improvement layers in the form of antireflective coatings on the top surface of the cover glass or plastic protective layer is desirable from the standpoint of increasing solar cell efficiency. Such films improve the transmission of infrared, visible and ultraviolet wavelengths of light through the cover glass or plastic protective layer, typically by providing a refractive index gradient to better capture incident light energy that otherwise would be reflected from the surface of the cover glass or plastic protective layer. Enhanced transmission of light energy to photovoltaic cells provides an advantage by increasing the number of photons available for electricity production. Energy transmission improvement coatings, again in the form of antireflective coatings, may also provide an advantage for glass windows by reducing the light reflected off of the surface, reducing the glare normally emanating from glass surfaces. Increased energy transmission, in the form of increasing the number of photons transmitted through the glass from outside a building to the inside of the building, may also reduce the need for interior electric lighting. Both photovoltaic panel cover glass and window glass are typically large and require even coatings of uniform thickness to be effective.
Thin film coating technologies have been developed and perfected for industrial scale production in window and solar panel manufacturing. As it has become known that thin-film antireflective coatings improve solar cell efficiencies, it has become desirable to now manufacture solar photovoltaic panels with such coatings in recent years. However, retrofitting older panels not originally coated with antireflective coatings requires dismantling of the photovoltaic array and sending the individual panels to a factory or facility for coating, an expensive and disruptive endeavor. Similarly for glass window panes installed on commercial buildings and storefronts, many may benefit from an antiglare coating, but are already installed and would need to be replaced with new pre-coated window panes, or by installing anti-glare sheets on the pane. Currently, there are no viable, cost effective solutions for retrofitting photovoltaic panels and window panes with high quality thin-film coatings.